Glucocorticosteroids are widely used for the treatment of seasonal allergic as well as perennial rhinitis. Intranasal glucocorticosteroids reduce inflammation of the nasal mucosa including edema. In addition, they are known to suppress the recruitment of polymorpho-nuclear and mononuclear cells, cytokine production, and, during maintenance treatment, both early and late-phase nasal reactions.
One of the glucocorticosteroids known for intranasal use is budesonide, 16.alpha., 17.alpha.-butylidenedioxy-11.beta.,21-dihydroxypregna-1,4-diene-3,20-dione .
Initially solid budesonide was used in pressurized metered dose inhaler (pMDI) preparations for intranasal administration, suitably dispensed from a specially adapted nasal inhaler. A recommended maximum daily metered dose of budesonide has been 400 .mu.g. Later on a nasal spray preparation for delivery from a spray device was prepared, containing budesonide in the form of an aqueous suspension. The same maximum daily metered dose as for the pMDI preparation was recommended. A third formulation is a dry powder formulation.
Both the nasal pMDI inhaler device and the aqueous nasal spray device are constructed to dispense a defined unit dose at each actuation. For example, a metered unit dose of 50 .mu.g has a recommended administration regime of one dose per nostril, four times daily, yielding a total of eight 50 .mu.g metered doses per day. Alternatively, a metered unit dose of 100 .mu.g would provide the same total metered daily dose (400 .mu.g) if administered to each nostril twice daily, for a total of four 100 .mu.g metered doses per day.
We have now surprisingly found that a lower metered unit dose of budesonide than that previously used can be administered safely and effectively to the nose.